Seamless metal tubes



WM. F. BROOKS,

OF NEW YORK, N. Y.

MAKING SEAMLESS METAL TUBES.

Specification of Letters Patent No. 14,551, dated Apri1 1, 1856.

To all lwhom t may concern Be it known that I, WILLIAM F. BROOKS, of the city and State of New York, have invented certain new and useful Improvements in Making Seamless Metal Tubes tand I do hereby declare that the following is a full, clear, and exact description of the sam'e, reference being made to the annexed drawings, making va part of this specification, in which similar letters refer to similar parts throughout the several figures.

This invention is an improvement in the construction of the roller dies for making seamless metal tubes and pipes, and for which Letters Patent were granted to Timothy D. Jackson under date Yof Feb. 28th, 1854.

Said improvement consists in beveling olf the corners of each of the rollers so that a series of grooves will be formed around the inner circumference. The object of forming these grooves is two-fold. The first is to ease the metal at the joints, the action of the rollers being such that by reason of their radial position the edges approach and leave each other at an angle. The consequence is that the metal of t-he tube, as it is being drawn through, rises up and is taken in by the sides, thus forming thin feathers at the joints, while at the same time this jams the set up so as to impede the free action of the rollers. The grooves therefore afford complete relief in this respect. The second purpose accomplished by this formation of ribs upon the tube is that thereby its subsequent separation from the mandrel may be effected. In all seamless tube machines heretofore it has been found necessary to use a taper mandrel in drawing the same through the reducing dies in order subsequently to effect the withdrawal of the mandrel. In my machine I use a mandrel of uniform diameter so as to have tubes of equal bore throughout. By subsequently passing the tube through another die, the rollers of which form a complete circle, (the size of which is slightly larger than the main body of the tube), the ribs are leveled and thereby the tube becomes slightly enlarged, thus relieving the mandrel.

The construction and operation is as follows: The manner of setting the rollers and their arrangement for regulation, &c., is as set forth in said before mentioned patent.

Each roller is however cut away at the corners, so that at the point of contact with each other, a groove is formed, as shown at (a) in Figure I, and in the enlarged view Fig. IV.

At (o) Fig. I is shown a section ofthe mandrel, and of the metal in the process of being formed into a tube; in which pro-cess said metal is forced into the several grooves (a) whereby a series of parallel ribs is formed upon the tube in the direction of its length.y After the tube has been reduced and shaped by passing through this die it must be loosened so as to allow Of its removal from the mandrel, and for this purpose, it must be slightly enlarged, and the importance of these projecting ribs will now be seen. For effecting the loosening the tube is forced through a second roller die in which the face of each roller is concave, the

whole cluster forming a circle slightly larger than that formed by the flat portions in the other die, as shown at (c) Fig. II, and .in the enlarged diagram Fig. V. In passing the tube through this die the projections are rolled down, by doing which the tube will be slightly distended by the pressing apart of the spaces between said ribs, thus completely loosening` it from its mandrel. In order to perform this operation with the greatest despatch, I place the two sets of dies together and parallel to each other, so that the centers shall be in line, and as shown in Fig. III, wherein A, represents the reducing and forming die, and B,`the loosener, the arrow indicating the direction of the tube in passing through.

What I claim as my invention and improvement in the reducing die herein described composed of an annular series of radial rollers, is-

The grooving, or removing the corners of said rollers, so that a series of parallel project-ions or ribs will be formed, upon the tube, the rollers relieved from undue strain, protected from choking, and the reduction of the tube, and the withdrawal of the mandrel therefrom facilitated, substantially as herein set forth.

WM. F. BROOKS.

Witnesses:

S. M. MAYNARD, FREDK. D. Soi/rens. 

